Swivel plug



R. S. MUELLERI swlvEL PLUG. APPLICATION FILED NOV- 23, 1916.

1,41 1,293, 4 Patented Apr. 4, 1922'.

W Ma/j y ,UNITED STATES PATENT OFFICE.

RALPH S. MUELLER, 0F CLEVELAND, OHIO, ASSIGNOR T0 BENJAMIN ELECTRIC MANUFACTURING COMPANY, A CQRPORATION OF ILLINOIS.

SWIVEL PLUG.

Specicatlon of Letters Patent.

Patented Apr. 4, 1922.

To all 'whom 'it may concer/n.:

Be it known that I, RALPH S. MUELLER,l

citizen of the United States, residing at Cleveland, in the county of C iyahoga and State of Ohio, have invented certain new and useful Improvements in Swivel Plugs, of which the following is a specification.

This invention relates to attachment plugs, and more particularly to swivel plugs, The objects of the invention are to provide an improved plug which is of simple form and cheap to manufacture; which is easily attached to the conducting wires;. which is convenient to operate in screwing it into the lamp socket; which can be separated to eX- pose th'e binding screws without removing screws or other parts; which relieves the cord strain; which amply protects the lead wires from liability of short circuit; and

finally a swivel plug comprising but two members which are readily connected or disconnected by relative rotation when desired and inl assembled form have a swivelling motion relative to each other, but nevertheless will not accidentally become disconnected. Further objects of the invention are in part obvious and in part will appear more in detail hereinafter.

The invention comprises the attachment plug hereinafter described and claimed.

In the drawings, Fig. 1 represents a side elevation of one form of plug embodyingthe invention; Fig. 2 is a central longitudinal section on the line 2 2, Fig. 3; Fig. 3 is an end view; Fig. 4 is a central longitudinal section on the line 4 4, Fig. 3, showing the two plug members partly connected, the cord being omitted; Fig. 5 is a side view of the insulated base or body; Fig. 6 is an end view thereof; and Fig. 7 is a detail section,

showing a modified form of cap and shell' connection. n

The plug shown in the drawings comprises essentially two members co-operatively associated, as will appear, one of which, marked 1, may be termed the base or body, and the other of which, marked 2, may be termed the ca or head. The two lead wires 3 of the con ucting cord are connectedv to the base or body while the cap turns relatively to the base or body in screwing the pluginto a socket, avoiding the necessity of twisting or entangling the cord.

The base or body 1 is made ofV suitable insulating material, such as rubber, fibre, composition material, porcelain or the like. It is cylindrical in form with a single longitudinal passage 4 extending lengthwise along its axis through which the two lead wires are threaded. The single passage enables both wires to be pushed through at the saine time, thereby saving time in assembling. At the advance end of the body, in other words the end first introduced into a socket, the base or body is rovided with a recess 5 communicating with the longitudinal passage 4, said recess in its bottom being provided with a threaded opening to receive the binding screw 6. This threaded opening is shown as a tapped opening in a nut 7 embedded in the material of the bod but of course, might be formed in the bo y itself or in a part otherwise attached tor the body. i The binding screw 6 passes through a smooth opening in an end plate 8 which has a portion marked 9 covering the longitudinal passage 4 and serving as an end contact, a bent intermediate portion 10 provided with an aperture 11 for the passage of the lead wire, and a depressed portionv 12 seated in the recess 5, as described, and serving as a base against which the lead wire is clamped by the head of the binding screw to produce good electrical connection between the lead wire and end contact, as will be readily understood.

The'other lead wire of the conducting cord is bent outwardly and then back on itself so as 'to lie in a radial recess 12*1 in the outer end of the base and in a longitudinal recess 13 in its outer surface. This double right angle turn of the-wire serves to .relieve an pull or strain on the cord and prevents pul ing the wires away fromthe binding posts to which they are attached.. In the inner end of the base is a curved groove or channel 14 in which is located a conducting member 15 having two small tongues 16 diametrically opposite each other and extendin radially outwardly a. short distance beyon the outer surface of the base. The conducting member 15 is preferably also slightly thicker tharithechannel in which it lies so that its surface is exposed beyond the end of the base, as shown vin Fig. 5, although this is not essential. 'Said member also has a longitudinal tongue 16 which extends down into the longitudinal recess 13, where it is 4 provided with a threaded aperture to receive a binding screw 17 for securing the end of` the lead wire, thereby electrically connecting said wire to member 15.

The cap or head 2 comprises a suitably shaped member 18'made of non conducting material, such as rubber, fibre', porcelaln,

' composition or'the like, or which can even with a flange 22 through which holdin tively to the body and forms the support -for ycarrying the threaded conductlng shell 21 which 'is screwed into the socket. Said shell is of the usual form and is suitably attached t0. the head. In Fig. 2 the shell is -provlded screws 23 are screwed into the head, while in'Fig. 7 the head is of composition molded around tongues or a flange 24 on the shell, thus producing a firm and substantially 1ntegral connection of the parts. The shell surrounds the body or base 1 and extends downtoward but stops short of the end of said body.in a manner to lea-ve the end contact 9 ex posed beyond the shell.

The swivellin' .movement between thel base and'cap is pro uced by the engagement of the t0n es k16 in an annular groove or chanlnel.25 1n the conducting shell 21. adjacentv the member 18. This channel is pressed in the metal and its innerdiameteris greater than the small ydiameter of the lshell across the roots of the threads therein. The ton es 16 project beyond the side surface of t e base or body and the diameter across said tongues is also greater than the diameter of the shell across the roots of its threads. Consequently when the tongues are fully seatedin the groove or channel'25, as in dotted lines, Fig. 4, theyxturn in said channel but cannot escape therefrom accidentally. At the same time the base or body is s i htly smaller than the shell and can be turne or tilted to a position askew therein. .By then rotating the ase and cap the tongues 16 can be entered in turn into the threads of the shell, thereby enablin l the two parts of the plug to. be separated y relative rotation and unscrewing movements, as shown in Fig. 4. The'eifect is ,due to the tongues forming an interrupted thread crossing the threads of the shell, as it were, because of the 4askewposition of the base 1n thebody. Relative rotation of the two parts in the opposite direction enablesv the two .arts to be assembled.

Qne .lstinct advantage of the plug -described 1s the absence of any distinction between the end capor head andthe ring usually attached to the threaded shell for turning it on the base. Both of these parts, in

the present plug, arev portions of the Same piece and it is impossible to accidentally twist the cord by turning the head instead of the ring. The plug can also be more readily inserted i-nto sockets provided with lamp shades where the ring is difiicult to reach and the head can bemore readily grasped. The

g tachable and detachable by 'relative rotation said threaded shell beingnon-rotatable with respect to the member which carries it, said members when in assembled position being capable of relative rotation without movement of disconnection.

r2. A swivel plug, comprising two members one carrying a'n end contact and the other f a threaded shell, and means whereby said members 4may be attached and detached with respect to each other by relative rotation and longitudinal movement, said threaded shell being non-rotatable with respect to the member which carries it, said members when in assembled position being capable of relaf tlve rotation without movement of discon v nection.

3. A swivel plug, comprising a base carry` ing an end contact, a head carrying a threaded shell, .and means whereby said base and head may be attached and detached with 4. A swivel plug, comprising a base carrysaid base .and having an annular channel to receive said projection.

6. A swivel plug, comprising a base having a contact at one end and a non yielding radial projection at the other end, means for electrically connecting the lead wires thereto,a threaded shell surrounding said base and having an annular channel to receive said projection, and a head supporting said shell and rotatable therewith, said head having .an opening therein the walls of .which form a guide for the conductor leading to the plug contact.

7. "A swivel plug, comprisingr a head carrying a socket engaging threaded shell provided with an internal annular channel, and a base carrying an end contact and provided witli an interrupted thread adapted to be passed through the threads of said shell into said channel.

8. A swivel plug, comprising a head carrying a socket engaging threaded shell provided with .an internal annular channelmand a base carrying an end contact and provided with an interrupted thread adapted to be passed through the threads of said shell into said channel, said interrupted threadforming .a art of the electrical connection of the lead wire to said threaded shell.

9. A-swivel plug, comprising a base having a -contact at one end and a radial projection at the other end, and a threaded shell 'surrounding said base and having an annular channel, said projection adapted to be passed through the threads o f said shell and Jforming part of the electrical connection of the lead wire thereto..

10. A swivel plug, comprising a base provided at one end with two diametrically opposite projections, .and a threaded shell s urrounding said base, saidv projections being adapted to be threaded through the threads of said shell.

11. A swivel plug, comprising a base provided at one end with two diametrically opposite projections, and a threaded shell surroundingsaid base, said projections being adapted to be threaded through the threads of said shell, said base having an end contact and an axial passage for leading the wire thereto.

12. A swivel plug, vided at one end with two diametrically opposite projections, and a threaded shell .surrounding said base, said projections being .adapted to be threaded through the threads of said shell, said base having" an end contact andan 'axial passage for leading the wire thereto and to the shell contact.

13. A swivel attachment plug comprising a threaded shell contact for screwing into a threaded socket, a handle secured to said threaded shell contact, an insulating base located substantially inside said threaded shell contact and having a swivel engagement comprising a base pro- I therewith, a center contact and binding terminal therefor supported by said insulating base, said threaded shell contact having an annular shoulder portion, and said-insulating base being provided with a non-yielding shoulder portion for cooperating with said annular shoulder portion, tending to hold said insulating base in said threaded shell contact, said insulating base being removable from said threaded shell contact at the inner end thereof.

14. A swivel attachment plug comprising l a threaded shell contact, a handle secured to said threaded shell contact, said threaded shell contact -having an annular yinternal shoulder, an insulating base having a cylindrical portion extending into said threaded shell contact and having a swivel engagement therewith, a wiring terminal supported by said .insulating base, said insulating base being provided with a non-yielding radially extending projection for engaging said annular shoulder, tending to hold said insulating base in position with the c lindrical portion within said`threaded shel contact member.

15. A swivel attachment plug comprising a threaded shell contact, a handle secured to said threaded shell contact, said threaded shell contact having an annular internal shoulder, an insulating base having a cylindrical portion extending into said threaded shell contact and having a swivel lengagement therewith, a wiring terminal supported by said insulating base, said insulating base being provided with a non-yielding radially extending projection for engaging said annular shouldery tending 'to hold said insulating base in position with the cylindrical portion within said threaded shell contact member, said insulating base being disconnectable from said threaded shell contact by -a linoveii'ient including a tilting movement.

16. A swivel attachment plug comprising a threaded shell contact, a handle secured to said threaded shell contact, said threaded shell contact having an annular internal shoulder, an insulating base having a cylindrical portion extending into said threaded shell contact and having a swivel engagement therewith, a wiring terminal supported by said insulating base, said insulating base being provided with a non-yielding radially extending projection for engaging said annular shoulder, tending to hold said insulating base in position with the cylindrical portion within said threaded shell contact member, said annular shoulder being at the outer end of the threaded shell contact.

17. A swivel attachment plug comprising a threaded shell contact, a handle secured to said threaded shell contact, said threaded shell contact having a shoulder, an insulating base having a cylindrical portion extending into said threaded shell contact and l having a swivel engagement therewith, a'

wiring terminal for said threaded shell contact supported by said insulatingbase, sald insulatlngf` base being provided witha nonyielding radially extending proJectlon for engaging said shoulder tending to hold said insulatin base with its cylindrlcal portion within sald threaded shell contact, Said projection being of metal and forming part of the electrical circuit between said threaded shell contact and its wiring terminal.

18. A swivel attachment plug comprising athreaded shell contact, a handle secured to said threaded shell contact, said threaded shell contact having an internalannular shoulder, an insulating base having a cylin-v drical portion extending'into sald threaded shell contact, a binding plate mounted on said insulating base, said binding plate. having a portion integral therewith forrnmg a non-yielding radially extendln proJectlon for engagin said 'annular shou der tending to hold sai insulatingbase with the cylindrical portion within said threaded shell contact.

19. A swivel shell attachmentyplug comprising a threaded shell contact, having an i' internal annular shoulder, an insulating base located substantially within said threaded shell contact, said threaded 'shell contact being swiveled with respect to Said insulating base, said insulating base being provided e with a non-yieldin shoulder for engaging said annular shou der portion tending to hold said insulating base in place in said threaded shell contact, said insulating base being insertible through the inner end of the J threaded shell Contact, and a wiring terminal supported by said insulating base.

20. A swlvel shell attachment plug comprising a threaded shell contact, having an internal annular shoulder, an insulatin base located substantially within sai threaded shell contact, said threaded shell contact being swiveled with respect to said insulating base, said insulating base being provided with a non-yielding shoulder for engaging said annular shoulder portion tending to hold said insulating base in place in said threaded shell contact, said insulating basebe'ing insertible through the inner end of the threaded shell contact, and a center contact supported by said insulating base.

, I n testimony whereof I alix my si ature.

RALPH S. MUEL ER. 

